The present invention relates to a cutting tool having an adjustable chip breaker, an exchangeable cutting plate supported on the chip breaker and on a mounting shaft of the cutting tool, and a clamping jaw which lies on the chip breaker and which is releasably connected to the cutting tool mounting shaft by a clamping screw member. The adjustable chip breaker is held in contact with the clamping jaw by a spring element which engages the chip breaker. The latter is provided with teeth on which the clamping jaw is supported.
In a cutting tool disclosed in German Offenlegungsschrift (Laid-Open Application) No. 1,477,328, a clamping jaw includes, in addition to an actual clamping component, a cylindrical guide member of substantial length which protrudes into a guide bore in a mounting shaft. The guide member is additionally provided with ribs to prevent undesirable rotation of the clamping jaw relative to the mounting shaft. The ribs also support a U-shaped bar whose end sections are positioned on both sides of the guide member to support a chip breaker. The chip breaker terminates in front of the clamping jaw guide member (as viewed from the front side of the cutting tool) and is provided on its surface with a plurality of extensively curved grooves. The clamping jaw is supported in one of these grooves by a tongue-shaped portion and is fastened in the mounting shaft by a clamping screw.
The above-described cutting tool has several drawbacks. Due to the cylindrical guide member and its ribs, which also serve to support the U-shaped bar, the tool is structurally very complicated and therefore expensive. Moreover, there exists the danger that the chip breaker, which is connected to the bar by a relatively short section, can become disengaged from the bar when the width of the chip breaker groove is changed, that is, when the chip breaker is moved relative to the clamping jaw. The absence of an accurate guidance and securement of the chip breaker has been found to have a particularly disadvantageous effect in case the cutting tool assumes a position other than that shown in the above German reference (in which the chip breaker is situated underneath the clamping jaw).